1. Field of the Invention
The present invention relates to the manufacture of semiconductor integrated circuit devices. More particularly, the invention provides a technique for fabrication of a titanium silicide film using TiCl.sub.2 on a gate electrode. The invention can also be applied to fabrication of source/drain regions, polysilicon interconnects, and other structures.
2. Description of the Related Art
Various techniques have been proposed to reduce the resistivity of a gate electrode by forming a titanium silicide layer thereon. These techniques, however, often consume a great deal of silicon from the gate electrode to form the titanium silicide. In some cases, the gate electrode is severely damaged(e.g., large gouges, grooves, etc.). Further, the flow of source gases was extremely difficult to control.
Furthermore, these technique often rely upon high temperature, which can cause impurities to diffuse from the gate electrode into the titanium silicide layer and often cause lower device reliability and other problems. Accordingly, conventional techniques for forming titanium silicide on gate electrodes suffer from numerous limitations and are therefore undesirable in most cases.
From the above it is seen that a technique for forming a gate electrode layer that is easy to implement, reduces resistivity, and can be performed at lower temperature is desired.